Heater construction



Aug. 24, 1937.

R. E. WILSON HEATER GGNSTRUCTION Filed Jan. 26, 1955 2 Sheets-Sheet l IN VEN TOR. ROBE/P75 W/LSO/V A TTORNEY HEATER CONSTRUCT ION Filed Jan. 26, 1935 I 2 Sheets-Sheet 2 I N V EN TOR. ROBE/PT E MLSO/V BY 7 ATTORNEY Patented Aug. 24, 1937 UNITED STATES 2,090,907 HEATER CONSTRUCTION Robert E. Wilson,.New York, N. Y., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana Application January 26, 1935; Serial No. 3,551

2 Claims.

This invention relates in general to heating apparatus and more especially to improvements in apparatus for heating hydrocarbon fluids to an elevated temperature, such as cracking tempera- .5 ture.

It is often desirable in heating hydrocarbon fluids to an elevated or cracking temperature to subject the tube surfaces through which '-the hydrocarbon fluid is being passed to intense heat, .10 preferably intense direct radiant heat, to rapidly accomplish the desired heating. One expedient for utilizing to the greatest extent the maximum heat absorbing surfaces of tubularelements is to expose said tubular elements, on both sides, to 15 intense direct radiant heat. As an arrangement for accomplishing the desired heating of tubular elements on both sides by intense direct radiant of combustion produced by the burners between 1 the banks of tubes is accomplished in such an ar- 'rangement by forming each bank of two rows of tubes in a vertical plane, the tubes of one row being staggered with respect to those of the other.

In heating tubes on both sides by intense radiant heat, it will be apparent thatv with tubes I 35 of any appreciable length sagging thereof intermediate their points of support may occur, this J being especially true of tubes intermediate the walls of the furnace arrangement.

In accordance with my invention, there is pro- -vided a furnace arrangement permitting of the i maximum radiant heat absorption by the tubes and the supporting of these tubes intermediate their ends which not only provides for additional load carrying members but also eliminates the to the intense heat to which they are subjected. For a better understanding of my invention,

reference is made to the accompanying drawings in which:

Figure 1 is a vertical sectional view of a heating apparatus constructed in accordance with my invention. I Figure 2 is a sectional View taken along line 2-2 of Figure 1.

55 Referring to the two figures in the drawings 45 objectionable sagging of the tubular elements due meansof a plurality of vertical banks of radiant heat absorbing tubes 6. Suitable burner arrange- 10 ments 1, either projecting through the side walls of the furnace structure I, as shown, or through the floor thereof, are disposed between each of t the vertical banks of radiant heat absorbing tubes 6 for separately supplying heat to each of the radiant heating sections 5. Other heat absorbing tubes may also be disposed within the furnace structure I. As shown, the convection chamber 3 may be provided with a plurality of suitably interconnected heat absorbing tubes 8 to be heated by convection heat 1 from the combustion gases flowing over the bridge wall! and a plurality of other suitably interconnected heat absorbing tubes 9 may be disposed adjacent the roof of the 'main heating chamber 2, in staggered relation, to be heated preponderantly by radiation from the combustion products from the burner arrangements 1, the tubes 9 also receiving some convective heat from the combustion products.

In Figure 1 there is shown an arrangement of tubes 6 comprising the vertical banks in the radiant or combustion chamber 2 of the furnace whereby each tube may be subjected to radiant {heat from the hot products of combustion produced by the burners I located on opposite sides of the tubes. This arrangement is characterized by the staggering of the tubes of one vertical rank of the bank with respect to the remaining vertical rank of the bank. Thus the sides of the 40 tubes of each rank closest to the hot products of combustion passing through each heating section are subjected to direct radiant heat therefrom and the sides of the tubes forming the other rank of each bank likewise receive radiant heat therefrom. Each of the banks of tubes forming the; heating sections is heated in this manner except the first and last single tube ranks located adjacent the front wall of the furnace and the bridge wall 4 respectively. These ranks of tubes are preferably-arranged to receive re-radiated heat. from the refractory of the front and bridge walls. In order to provide suitable support for the tubes 6 forming the various radiant heating sections 5 intermediate the front wall of the furnace structure and the bridge wall 4, there is provided, as shown in Figure 2, a plurality of vertical columns H positioned intermediate the side walls of the furnace setting I. Each of the vertical columns ll may comprise a suitable metallic I-beam I2 surrounded by refractory material l3 to protect the I-bearn from the intense heat within the furnace structure. The columns H are of comparatively small size with respect to the size of the combustion chamber 2 and only a negligible shielding of the tubes by these columns is effected.

As contemplated by my invention, the column II is used to support the horizontal tubes 6 forming the radiant heating sections 5. As shown, a plurality of tube supports I4 are suitably attached to the column II for supporting the individual tubes 6 intermediate their ends. The supports 14 preferably take the form of brackets and are of refractory metal such as chromium alloys. They may be suitably joined to the I-beam l2 encased in the refractory material 13. Any suitable form of individual support members 14 may be used. It will be evident from the foregoing that each of the individual tubes 6 intermediate the tubes disposed adjacent the front wall of the furnace setting I and the bridge wall 4 is provided with a separate support for carrying the load thereof. Similar supports may also be provided for the tubes adjacent the front wall and the bridge wall 4. 7

While I have shown in Figure 2 two columns ll intermediate the side walls of the furnace setting, it is to be clearly understood that more or fewer columns may be provided to provide more or fewer points of support, as the case may be, for the tubes 6 forming the sections 5. For instance, a single column may be positioned in about the middle of the main heating chamber 2 between each staggered row of tubes 6 to accomplish the desired additional support for the tubes, the number of columns of course depending upon the length of the tubes.

-While I have shown a specific structure for the columns II, it is to be clearly understood that the structure shown is merely for illustrative purposes and may be varied without departing from the scope of the invention. For instance, the columns ll maybe made entirely from nonmetallic refractory material or from refractory metal with the individual tube supports suitably anchored thereto.

There is shown in Figure 1, the flow preferably employed in heating oil to the desired temperature in an apparatus of the: type disclosed. As illustrated, the hydrocarbon fluid to be heated is introduced into a line 15 and passed through the heat absorbing tubes 8 in the convection heating chamber 3 wherein it is preheated. From the heat absorbing tubes 8 .the fluid may be conducted through the roof tubes 9, from the top row to the bottom row,both of which are suspended from the roof of the furnace in the conventional manner, thence through the vertical bank of tubes I6 adjacent the front wall of the furnace structure from which it is conducted through the intermediate radiant tubes 6 in the manner illustrated. The course of the hydrocarbon fluid through the radiant .tubes 6, as may be seen by the schematically illustrated header connections, is from the lower end of the row l6 downwardly through the next adjacent of the two ranks making up the first vertical bank of tubes 6 and upwardly through the rethrough all of the tubes, the tubes may be arranged in multiple in the manner explained in my referred-to co-pending application. While I have shown the fiow of hydrocarbon fluid through the convection tubes 8, the roof tubes 9 and the radiant-tubes l6, 6 and H in the order named, it may be found for some purposes an arrangement wherein the oil flows from the convection tubes into and through the radiant tubes I6, 6 and I1, andthereafter through the roof tubes 9 ismore desirable; or, if desired, the oil may flow through the convection tubes 8, then to the upper roof tubes 9, thence to the front wall tubes l6, from which the oil may be passed to the bridge wall tubes [1. From the tubes 'l'l the oil may be passed through the tubes 6 and the lower roof tubes'9 or vice-versa. In this manner, control of heat input may be improved. It will be clearly understood that the'flow of oil through the various tubes in the furnace setting may be varied without departing from my invention.

As an aid in rapidly heating the hydrocarbon fluid to the desired temperature in a furnace of the type illustrated, the various heat absorbing tubes may be of relatively small diameter with respect to the size of tubes customarily employed in the conventional type of oil heating apparatus. The use of small tubes is particularly advantageous when the'fluid passing through the furnace structure, especially the radiant or main heating section thereof, is divided into a plurality of parallel streams. Such an arrangement makes possible a larger ratio of heating surface of hydrocarbon fluid volume being treated in any one tube.

While I have shown and described the preferred embodiments. of my invention, I wish it to be understood that I do not confine myself 'to the precise details of construction herein set forth by way of illustration as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

1. In an apparatus for heating hydrocarbon fluids, to conversion temperature, a main heating chamber, a plurality of interconnected horizontal tubes exposed within said chamber and arranged in a plurality of banks disposed in vertical planes and spaced apart to divide the main heating chamber into a plurality of parallel sections, means for producing hot products of combustion disposed in each of said sections between said banks for heating the exposed tubes thereof, on both sides, preponderantly by direct radiant heat from said combustion products, a pluralityof refractory columns adjacent said banks of tubes within said main heating chamber arid spaced from each other and the walls thereof, and .a plurality of hangers connected to each of said columns for individually supporting each of the tubes forming the parallel sections intermediate their ends.

2. In an apparatus for heating hydrocarbon fluids, to conversion temperature, a main heating chamber defined by vertical walls, a roof and a floor, a plurality of interconnected horizontal exposed tubes within said chamber and arranged in a plurality of banks disposed in vertical planes and spaced apart to divide the main heating chamber into a plurality of parallel sections, the banks of tubes intermediate the walls of said heating chamber for forming the parallel sections being arranged in a plurality of parallel ranks of exposed tubes spaced from each sides, preponderantly by direct radiant heat from 10 said combustion products.

ROBERT E. WILSON. 

